Elastomeric compositions are well known in the art. Further, it has long been known in the field of disposable absorbent articles that it is desirable to construct absorptive devices, such as disposable diapers with fasteners, pull-on diapers, training pants, sanitary napkins, pantiliners, incontinence briefs, and the like, with elastic elements to improve the ease of motion and maintenance of a sustained fit. Furthermore, elastic elements allow the diaper to accommodate a range of different sized wearers. A diaper may have elastic elements in a number of its structures including the waist band, leg cuffs, side panels, elasticized topsheets, and backsheet. Diapers and other absorbent articles fitted with elastic elements, such as elasticized leg cuffs or elasticized waist bands, providing comfortable fit and leakage control are known in the art.
Many elastomeric compositions used to form elastic elements within current diapers are variants of synthetic rubber compositions. However, these elastomeric compositions tend to retract relatively rapidly when released from a stretched state. This complicates application of the absorbent article onto the wearer.
During application, a diaper generally may be stretched and elongated longitudinally and/or laterally from its initial substantially compacted and untensioned state. Upon release of the elongating tension, the diaper often contracts, constricts, and/or folds before it can be successfully applied to or adjusted on a wearer. In traditional taped diapers, the diaper generally is stretched longitudinally prior to application onto a wearer. However, if a continuous force is not maintained, the diaper will quickly retract. Generally, a caregiver needs to apply a continuous elongating force to the diaper while at the same time positioning the diaper onto the wearer and tending to the wearer who may uncooperative (e.g., crying, fussing, moving, resisting, etc.) in the diapering process. These multiple simultaneous requirements may lead to frustration for the caregiver. The multiple simultaneous requirements may result in the diaper being positioned improperly on the wearer.
Similarly, in pant-type articles, the waist region generally must be stretched and elongated to enlarge the waist opening from an initial substantially constricted and untensioned state. The waist often requires a continuous force to be applied during the application process, generally by a caregiver or wearer, to counteract the rapid retraction of the waist opening that would be experienced without a continuous application of the force. Leg openings in pants-type articles also tend to retract quickly and/or constrict the leg with force during application, increasing the difficulty of pulling the article up to the desired location on the wearer's upper thigh. Applying a continuous force to maintain an enlarged waist opening may be difficult for young children who lack the hand strength and dexterity to apply the continuous force while simultaneously pulling on the pant.
Recent diaper advancements have focused on the acceptance and storage of feces. In conventional diaper designs, feces remain between the diaper's topsheet and the wearer's skin. As a result, the wearer experiences excessive soiling, irritation, and the potential of leakage generally around the leg cuff. Advances in diaper design include the use of an apertured elasticized topsheet to isolate feces away from the wearer's skin thus preventing leakage and irritation. The apertured elasticized topsheet forms a void between the elasticized topsheet and the underlying diaper structure. The elastic within the elasticized topsheet aids in keeping the elasticized topsheet substantially in contact with the wearer's skin. Furthermore, the elastic aids in keeping the aperture positioned so as to receive fecal insult.
While elasticized topsheets are conceptually advantageous, diapers with elasticized topsheets comprising conventional elastomers are often difficult to apply. Application of the diaper requires a caregiver to stretch the diaper so that it is in a substantially planar position. Upon release, the elastic within elasticized topsheet contracts at a rate that makes it difficult for the caregiver to position the diaper correctly onto the wearer. This “snap-back” of the elasticized topsheet may increase the difficulty of applying the diaper to the wearer. If the diaper is difficult to apply, there may be a tendency for mispositioning the aperture. A mispositioned aperture may result in fecal deposit on the elasticized topsheet rather than through the aperture within the elasticized topsheet. Mispositioning of the aperture can destroy the benefit of isolating feces from the wearer's skin. Examples of diapers comprising an elasticized topsheet having an aperture have been disclosed in U.S. Pat. No. 4,892,536, issued to Des Marais et al. and U.S. Pat. No. 4,990,147 issued to Freeland.
Thus, there is a need for an absorbent product comprising elastomeric compositions that retract slowly upon being released from a stretched state, thus facilitating application and positioning of the product correctly onto the wearer.